Blade servers capable of power supply and air-conditioning management of blades in an integrated manner are recently used in offices so as to save office space. A blade server is configured by connecting blades to a housing disposed with insertion ports for attaching and removing blades.
Software used on these blades can easily be duplicated and modified and may be used without authorization. Therefore, a vendor supplying the software incorporates a software lock into the software to prevent unauthorized use of the software or an optional function of the software. A license key for permitting the use of software is given only to licensed users.
The vendor may lock a license key for software (particularly, valuable software) to blade-specific information such that only one certain predefined blade fixedly uses the software (node-locked license). The blade-specific information is a Media Access Control address (MAC address) or World Wide Name (WWN), for example.
On the other hand, a vendor sets the number of licenses that can concurrently use software on a network (hereinafter referred to as “usable number”) in some licensing methods. If the number of licenses concurrently using software (hereinafter referred to as “usage number”) is within a limit of the usable number, users can freely use the software (floating license).
In the case of the floating license, a license management unit is provided that connects with multiple blades via a local area network (LAN) to manage the number of issued license keys over a network. The license management unit issues license keys and manages the number of issued license keys such that the usage number does not exceed the usable number, thereby preventing unauthorized use of software. The license can be transferred via a LAN between blades.
For examples of such technologies, refer to Japanese Laid-Open Patent Publication Nos. 2008-107879, 2008-158639, and H5-346851.
However, the node-locked license requires all the blades possibly using software to have licensing. Therefore, even a blade of a standby system not operated in a normal situation must have licensing. If a blade is replaced, blade-specific information is different between before and after the blade replacement and, therefore, the license of the blade before replacement is not usable for a blade after replacement, preventing prompt transfer of licensing, causing a problem in that licensed operation is disrupted.
On the other hand, the transfer of license through a LAN in the case of the floating licensing causes a problem in that software may be used without authorization by intentionally detaching a blade from the LAN during transfer of licensing. It is also problematic that software may be used without authorization by improperly modifying a management unit, for example, by rewriting the usable number or the number of issuance.